curl: curl: SSH host verification bypass when using schemeless URLs with SFTP/SCP

A flaw was found in curl. When a user invokes curl with a schemeless URL and specifies SFTP SSH File Transfer Protocol or SCP Secure Copy Protocol as the default protocol, the tool layer fails to initialize critical SSH security options. This bypasses host verification, allowing curl to connect t...

curl: curl: Man-in-the-middle attack via SSH host key bypass

A flaw was found in curl. When a libcurl-based application uses SCP:// or SFTP:// for transfers and employs the CURLOPTSSHKEYFUNCTION callback, it may silently accept an untrusted server. This occurs if the server's host key type differs from the one stored in the knownhosts file. The callback...

Security Bulletin: Multiple vulnerabilities impacts AIX due to cURL libcurl (CVE-2026-1965, CVE-2026-3783, CVE-2026-3784)

Summary Multiple vulnerabilities in the curl/libcurl are related to unauthorized access. Vulnerability Details CVEID:CVE-2026-1965 DESCRIPTION: libcurl can in some circumstances reuse the wrong connection when asked to do an Negotiate-authenticated HTTP or HTTPS request. libcurl features a pool o...

USN-8487-1: curl vulnerabilities

Andrew Nesbitt discovered that curl could reuse an existing live connection during STARTTLS-based connection upgrades even when the TLS configuration did not match. A remote attacker could possibly use this issue to cause curl to use an unintended TLS configuration. CVE-2026-8286 Muhamad Arga...

mariadb: Arbitrary shell command execution via improper sanitization in CONNECT engine

A flaw was found in MariaDB server. When the CONNECT engine is installed and REST support is enabled on Windows, a user can exploit improper sanitization of the table HTTP attribute. This attribute is interpolated into the curl command line, allowing for arbitrary shell command execution on the...

mariadb: Arbitrary shell command execution via improper sanitization in CONNECT engine

A flaw was found in MariaDB server. When the CONNECT engine is installed and REST support is enabled on Windows, a user can exploit improper sanitization of the table HTTP attribute. This attribute is interpolated into the curl command line, allowing for arbitrary shell command execution on the...

Security update for curl

This update for curl fixes the following issues CVE-2026-4873: connection reuse ignores TLS requirement bsc1262631. CVE-2026-5545: wrong reuse of HTTP Negotiate connection bsc1262632. CVE-2026-5773: wrong reuse of SMB connection bsc1262633. CVE-2026-6253: proxy credentials leak over redirect-to...

SUSE-SU-2026:2703-1 Security update for curl

This update for curl fixes the following issues - CVE-2026-4873: connection reuse ignores TLS requirement bsc1262631. - CVE-2026-5545: wrong reuse of HTTP Negotiate connection bsc1262632. - CVE-2026-5773: wrong reuse of SMB connection bsc1262633. - CVE-2026-6253: proxy credentials leak over...

mariadb: Arbitrary shell command execution via improper sanitization in CONNECT engine

A flaw was found in MariaDB server. When the CONNECT engine is installed and REST support is enabled on Windows, a user can exploit improper sanitization of the table HTTP attribute. This attribute is interpolated into the curl command line, allowing for arbitrary shell command execution on the...

mariadb: Arbitrary shell command execution via improper sanitization in CONNECT engine

A flaw was found in MariaDB server. When the CONNECT engine is installed and REST support is enabled on Windows, a user can exploit improper sanitization of the table HTTP attribute. This attribute is interpolated into the curl command line, allowing for arbitrary shell command execution on the...

curl: ssh_config_matches is dead code: unauthorized SSH key reuse

Summary libcurl's SSH connection-reuse guard sshconfigmatches — added for CVE-2022-27782 and reaffirmed by CVE-2023-27538 — is dead code in every release since 7.83.1. It compares sshc-rsa / sshc-rsapub between a new transfer "needle" and a pooled connection, but on both sides those pointers are...

curl: mbedTLS / wolfSSL / rustls backends silently skip hostname verification when CURLOPT_SSL_VERIFYPEER=0

Summary When an application sets CURLOPTSSLVERIFYPEER=0 while keeping CURLOPTSSLVERIFYHOST=2 the default, the mbedTLS, wolfSSL, and rustls TLS backends silently skip the hostname-vs-certificate check. The OpenSSL, GnuTLS, and Schannel backends correctly preserve hostname checking under the same...

Multiple vulnerabilities impacts AIX due to cURL libcurl (CVE-2025-14819 CVE-2026-1965 CVE-2026-3783 CVE-2026-3784 CVE-2026-5545)

IBM SECURITY ADVISORY First Issued: Fri Jun 26 01:16:13 CDT 2026 The most recent version of this document is available here: https://aix.software.ibm.com/aix/efixes/security/curladvisory10.asc Security Bulletin: Multiple vulnerabilities impacts AIX due to cURL libcurl CVE-2025-14819, CVE-2026-196...

Curl 8.15.0 < 8.21.0 SASL Double-Free

The version of curl installed on the remote host is 8.15.0 prior to 8.21.0. It is, therefore, affected by a double-free vulnerability: - The curl logic that works with SASL authentication could end up cleaning up the GSASL context twice without clearing the pointer in between, making it free the...

Curl 8.16.0 < 8.21.0 WebSocket Auto-PONG Memory Exhaustion

The version of curl installed on the remote host is 8.16.0 prior to 8.21.0. It is, therefore, affected by a denial of service vulnerability: - Because curl lacks an upper bound on memory allocation for unacknowledged WebSocket frames, a malicious server can exhaust all available memory by floodin...

Curl 7.30.0 < 8.21.0 Wrong STARTTLS Connection Reuse

The version of curl installed on the remote host is 7.30.0 prior to 8.21.0. It is, therefore, affected by an improper certificate validation vulnerability: - A vulnerability exists where a new transfer that uses STARTTLS to upgrade the connection might reuse an existing live connection even thoug...

Curl 7.46.0 < 8.21.0 Trailing Dot Domain Super Cookie

The version of curl installed on the remote host is 7.46.0 prior to 8.21.0. It is, therefore, affected by a cookie injection vulnerability: - A flaw in curl's cookie parsing logic allows a malicious HTTP server to set super cookies that bypass the Public Suffix List check. CVE-2026-8924 Note that...

libcurl 8.13.0 < 8.21.0 Use-After-Free in Socket Callback

The version of libcurl installed on the remote host is 8.13.0 prior to 8.21.0. It is, therefore, affected by a use-after-free vulnerability: - Calling curleasypause within the event-based CURLMOPTSOCKETFUNCTION callback triggers a use-after-free vulnerability. CVE-2026-9080 Note that Nessus has n...

Curl 8.18.0 < 8.21.0 QUIC Zero-Length UDP Datagrams DoS

The version of curl installed on the remote host is 8.18.0 prior to 8.21.0. It is, therefore, affected by a denial of service vulnerability: - An issue in curl's QUIC UDP receive function allows a malicious HTTP/3 server to trigger a remote denial of service by continuously streaming empty...

Curl 8.11.0 < 8.21.0 HTTP/3 Early Data Information Disclosure

The version of curl installed on the remote host is 8.11.0 prior to 8.21.0. It is, therefore, affected by an information disclosure vulnerability: - When libcurl returns to a hostname with a cached SSL session and early data enabled, libcurl might send the request bytes before enforcing the...